1. Field of the Invention
The present invention relates to an electronic equipment anti-theft monitoring system. More specifically, the present invention relates to a system, device and method for selectively monitoring electronic equipment by injecting an RF current into the power supply lines of the electronic equipment and monitoring return of the injected RF current through a front-end noise suppressor capacitor mounted across the power supply lines within the electronic equipment.
2. Description of the Background Art
Due to the rapid evolution in electronic technology, the majority of electronic devices presently used comprise complex circuits, such as switching power supplies for example, which emit radio signals as noise. To eliminate the radio signal noise within the device, front-end noise suppressor capacitors are commonly installed in parallel across the power supply lines to eliminate pulse and various noises generated by the complex circuitry and noise which originates externally of the device which may contribute to device malfunction. For instance, computers, monitors, printers, televisions and VCRs which accommodate a switching power supply normally utilize a front-end noise suppressor capacitor to eliminate the above-mentioned noises.
Normally, the front-end noise suppressor capacitors are of large capacity in the range of 0.05.mu.F-1.00.mu.F to suppress a wide frequency range of radio signals. Accordingly, the front-end noise suppressor capacitors are normally disposed in the circuit before the power switch of the electronic equipment in order to protect the contact points of the power switch from sparks and to also eliminate any generated noise. Generally, if noise is sent through one side of the power supply line from external the electronic device, the frontend noise suppressor capacitor serves to return the noise to its source through the other side of the power supply line.